Hello,
There's something that we seem to have overlooked (or at least I haven't seen it discussed): Apple's supply chain.
For each new product that Apple creates, they usually have the BOM (bill of materials) bought and paid for, for the entire life-cycle of the device, before they even build the first one. So, for instance, if they plan to sell 100 million iPhone 5's before the iPhone 6 comes out, they've already bought all of the parts for those 100 million iPhone 5's. Tim Cook is the master of the supply chain, and deservedly so. That's why the other manufacturers are having such a hard time coming up with an iPad-killer, because they can't get the price down and still make a profit. Apple drives the prices up for everybody else.
What does that mean to the customers on this thread? It means that Apple is probably stuck with a lot of crummy LG displays that they need to get rid of. I'm almost certain that all rMBP LG Retina displays will experience image retention over time, but severe cases like mine and Dr. Sly's (and others) might indeed be rare. The milder cases of LG IR will likely go unnoticed for the most part, so Apple can hedge it's bets and simply keep selling them until they're gone. The complainers will either get their screens replaced with a Samsung display (which seems likely) OR they will keep playing the lottery every 14-days until they get a new rMBP with a Samsung display (which seems statically less likely).
So, it seems to me, if I were Apple (and had less scruples), I would set aside all of the Samsung displays (which there seems to be a lot less of) for repairs to placate the "picky" people (i.e. people like us who want what they paid for) and I'd set aside all (or at least most) of the LG displays for production (where there'd be a better chance that they'd get into the hands of customers who wouldn't notice the IR issue). If Apple is thinking like this, and if they've made adjustments based on just such a mindset, then Samsung displays are likely even less prevalent in production units than they were before. If that's what's happening, then it may be better to hold onto an otherwise perfect rMBP with LG display until after the 14-day waiting period and then take it in for repair.
Anyway, that's just something to think about.